RF communication systems may use RF PAs to provide RF transmit signals. Power levels of the RF transmit signals may be relatively high to achieve required transmit distances. As such, for high efficiency, the RF communication systems may use switching power supplies to provide power for amplification to the RF PAs. Further, at high output power levels, the RF PAs and the switching power supplies may utilize envelope tracking of the RF transmit signals to maximize efficiency. In envelope tracking, a switching power supply provides an envelope power supply signal to an RF PA. The envelope power supply signal at least partially envelope tracks an envelope of an RF transmit signal, which is provided by the RF PA. However, at low output power levels from the RF PA, the RF PA and the switching power supply may use average power tracking instead of envelope tracking. In average power tracking, the envelope power supply signal is held at a constant magnitude. The magnitude of the envelope power supply signal may be adjusted as an average output power from the RF PA is adjusted.
In this regard, when the average output power from the RF PA is relatively high, the RF PA and the switching power supply may use envelope tracking. Conversely, when the average output power from the RF PA is relatively low, the RF PA and the switching power supply may use average power tracking. However, in certain situations, when transitioning from envelope tracking to average power tracking, the switching power supply may introduce a disruption into the envelope power supply signal. Such a disruption may interfere with proper operation of the RF PA. Thus, there is a need to reduce or eliminate disruptions of an envelope power supply signal when transitioning from envelope tracking to average power tracking.